The present invention relates to a method for manufacturing a magnetic disk drive in which a magnetic head is heated by a heater to control the flying height from a magnetic disk medium to the magnetic head so that write performance and read performance are improved.
In recent years, magnetic disk drives such as hard disks have achieved widespread use not only for computer equipment but also for home electric appliances such as hard disk recorders. Each of such magnetic disk drives comprises a magnetic disk medium and a magnetic head. The magnetic head magnetizes the magnetic disk medium while flying above it, and also reads a magnetized state of the magnetic disk medium, thus writing and reading information thereto and therefrom. Here, for example, when information is written, with the decrease in clearance between the magnetic disk medium and the magnetic head, the expansion of a magnetic field formed by the magnetic head can be further decreased. As a result, the area magnetized on the magnetic disk medium becomes smaller. In other words, in order to increase the recording density of the magnetic disk drive, it is necessary to decrease the clearance between the magnetic disk medium and the magnetic head, i.e., the flying height of the magnetic head.
Conventional approaches for decreasing the flying height of the magnetic head include a technology in which a heater formed of a thin film resistor is placed in proximity to a magnetic head device so as to heat a magnetic head to cause thermal expansion, thereby allowing the magnetic head to get closer to a magnetic disk medium. In this case, the flying height of the magnetic head changes in response to a situation in which a magnetic disk is used (e.g., the use environmental temperature, a zone of the magnetic disk medium that is a target to be written/read, and operation modes such as write and read). Therefore, it is necessary to control the amount of heating by the heater in response to the use situation.
As a specific example, there is disclosed a magnetic disk drive capable of controlling the amount of heating by a heater. In this magnetic disk drive, a control table for associating a use situation with control parameters such as the amount of heating by the heater is stored beforehand. When the magnetic disk drive is used, the control table is referred to so that the amount of heating by the heater is determined in response to the use situation. See, e.g., Japanese Patent Laid-open No. 2004-79126 (patent document 1).